The video I linked was doctors who specialise in fitness doing a literature review of the evidence of what I was discussing as published in medical journals and talking about the actual, medical, biomechanics.

"by using obscure and invented health industry terminology absent from medical science"

"Zone 2 HR" is just an alias for 65%-75% of your max heart rate with Zone 3 being 80%-85% and so on ... very simple, and max HR % is used across the medical profession (along with VO2 Max) [1][2][3][4] ... I could go on and on.

These "zones" are defined by the point at which metabolic processes change. After ~zone 2, you burn more glycogen and engage fast twitch muscles, and this affects cellular respiration differently in terms of performance pay-off. At ~zone 3 the metabolic processes and chemical balances change again, and so on [5]

You VERY evidently have so little idea about what you're actually talking about, at this point I consider it a troll and I won't bother continuing.

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6607712/ [2] https://journals.physiology.org/doi/full/10.1152/physiol.000... [3] https://www.researchgate.net/publication/259652575_From_Hear... [4] https://escholarship.org/content/qt5cz1v976/qt5cz1v976.pdf [5] https://physoc.onlinelibrary.wiley.com/doi/full/10.14814/phy...